Method of separating minerals.



"I all whom it may concern:

, may be separated from the gangue material UNITED stratrns PATENT QFF/ICE- j ALEXAND R s. Barman-or nn'rnorr, MICHIGAN, AssfGNon. 'ro CHEMICAL DEVELOP,-

- Mair: 00., oriaurrato, New roan, aconronarion or coiioaeno.

Jl/IETEQD' or snmna'rme mmnnars.

Ilo Drawing.

, Beit' known that I, ALEXANDER S. RAMAGE, a c1t1aen' of the United :States, residingat Detroit, in the county of Wayne and State of Michigan, have invented certain new and.

useful Improvements in Methods of Separating Minerals,of which the following is a specification. i I

The object of this inventionis' the provision of amethod' whereby a mineral may be separated from the gangue materialyor one or more component minerals of a complex mixture may besucces'sively separated, by hydrometallurgical or flotation 3 processes. It is wellknown that certain minerals, as forinstancethe s'ulfids of zinc,leadand iron by flotation in acid solutions, the liquids more commonly employed being heated solutions of sulfuric acid or acid sulfates.- I have discovered that under proper'condi tions as hereinafter set forth it is possible to effect a successive separation of several mineral components of a complex mixture or ore by appropriately varying the conditions existing in a single solution. In order to accomplish this result I make-use of a solution containing a constituent capable of reacting selectively, at proper temperatures, upon one or'more of the componentminerals.

in order that the invention may be fully understood I will describe the same by refer- .ence to a specific example, it being understood that the mvention is not restricted to' the conditions specified in this example. In

the case of anore containing sulfids of zinc,

I lead and iron- I may employ a 10% $0111 tion of sodium nitrate or Chile saltpeter, together with sulfuric acid, yielding free nitric acid and acid sodium sulfate. pulverized and properly graded ore-is subjected'to-this solution at a temperature of approximately 140 F., whereupon the zinc sulfid rises to the surface in the form of a spongy-mass which may readily be skimmed.

oil". The temperature is then raisedto approximately 180 1 -whereupon the iron sulfid rises to the surface and may be similarly removed, leaving a mixture of galena with the gangue. material. This galena may be readily separated by known concentration methods. @Under proper conditlons there is no 'substantial solution of the min- .erals and with care a nearly perfect separa- The tion, amounting in some cases to 98%, may be secured. The liquor is used repeatedly, replacing the necessary losses of nitrate and sulfuri'c'acid. The peculiarity of this separation'is that the zinc sulfid rises in a spongelike mass which can be readily washed from any mechanically entangled compact pyrites.

trated than above described, the temperature most favorable for the"s' eparation varying with the concentration of the solution.

For, separating the above-described mine'ral's, a solution of sodium chlorid and sul furic acid may also be used, but the separation is somewhat less" rapid -and complete.

.ive in -t he separation off chalcociteyand chal- .copyrite.

The presence of limestone, dolomite, or

consumption 'o r jloss of 'c'onsiderable quantities of acid, and in case such compounds are present theores maybe subjected to" a preliminary acidtreatment, preferably with hydrochloric acid." In'case fumes of sulfur dioxid are available from roasting furnaces,

pared 'by passing these fumes over sodium known manner. Even when the amount of carbonates present is but small, it is desirable to decompose tliem by an acid treatment in order that no carbon dioxid may be evolved during the flotation, inasmuch as this gas appears to render the separation several mineral component-s.

VVhil'e it is impractical to state definite temperatures or concentrations which are effective inbringing about the desired sepa- 'very readily and simply accomplished by slowly increasing the temperature of the solution to the point at which one mineral component floats, andmai'ntaining' the solution at or near this temperature, or belowthe temperature at'which the second component rises, until the first component is removed. A further rise of temperature will then bring about the separation of the second component. should not be heated'to a temperature substantially above that atavhic'h a given separation occurs until the separated component has been removed. 7

The nitric acid solution is also highly effectsimilar materials will naturally result in the.

the hydrochloric acid is conveniently, pre-' -chloridin heated cylinders .in the well -less exact by actingindiscriminately on the In general, the solution.

Specification of'LettersPatent. Patented Aug. 16, 1910. Application filed December 12, 1908. Serial no. 467,1,5t3.

The solutions may be more or less concenration in all-cases, the" separation'may be In case of free metals I may use the above named solutions, or a solution ofsodium chlorid or sodium sulfate containin free caustic soda. The process is likewise applicable to the. separation of a single mineral from. a gangue material. For example I have found that zine sulfid disseminated through a gangue of dolomite may be successfully treated as follows: The ore is first mechanically concentrated, say to a 30% concentrate, and is then immersed in a highgravit-y solution containing for example 10% of sodium nitrate to which sulfuric acid as been added, referably in proporium sulfate. Efi'ervvescence occurs at first but ceases in a short time as the gangue material becomes coated with sulfate. At a temperature approximating 140 F., the zinc sulfid is found to rise'with substantial completeness, an ex amination of the gangue showing only 0.22% of' zinc remaining therein. The acid liquid in this case'reaets directly with the mineral particles, enveloping them in a gaseous sheath or envelop by which they are elevated. For the best results the ore should be ground to number ten mesh or finer, as if the particles are larger than this there is a tendency for the gas to escape in the form of bubbles without exerting its full efiiciency in raising the mineral.

I claim 1. The method of treating ores containing a plurality of mineral components, which consists in immersing the ore in a suitable solution, separately floating said mineral components by progressively raising the temperature of the solution, and removing at each rise of temperature the product separated during such rise.

'2. The method of treating ores containing a plurality of mineral components, which consists in immersing the ore in a suitable solution containing free nitric acid, separately floating said mineral components by progressively raising the temperature of the solution, and removing at each rise of temperature the product. separated during such use.

In testimony whereof, I afiix my signature in presence of two Witnesses.

ALEXANDER s. RAMAGE.

lVitnesses i CHARLES H. Po'rrER, N. P. LEONARD. 

